CN114823025B - Low-eddy-current-loss neodymium-iron-boron magnet - Google Patents
Low-eddy-current-loss neodymium-iron-boron magnet Download PDFInfo
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- CN114823025B CN114823025B CN202210503926.7A CN202210503926A CN114823025B CN 114823025 B CN114823025 B CN 114823025B CN 202210503926 A CN202210503926 A CN 202210503926A CN 114823025 B CN114823025 B CN 114823025B
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- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 85
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 65
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 65
- 238000009792 diffusion process Methods 0.000 claims abstract description 39
- 239000002002 slurry Substances 0.000 claims abstract description 17
- 239000000843 powder Substances 0.000 claims description 28
- 229910045601 alloy Inorganic materials 0.000 claims description 18
- 239000000956 alloy Substances 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 14
- 230000032683 aging Effects 0.000 claims description 13
- 238000005520 cutting process Methods 0.000 claims description 13
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 claims description 12
- 238000010438 heat treatment Methods 0.000 claims description 12
- 239000002904 solvent Substances 0.000 claims description 12
- 238000005324 grain boundary diffusion Methods 0.000 claims description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 10
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 claims description 10
- 229910052771 Terbium Inorganic materials 0.000 claims description 7
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 6
- 239000004593 Epoxy Substances 0.000 claims description 6
- 238000000227 grinding Methods 0.000 claims description 6
- 239000003973 paint Substances 0.000 claims description 6
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 5
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 5
- 229910052721 tungsten Inorganic materials 0.000 claims description 5
- 229910052720 vanadium Inorganic materials 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 4
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 claims description 4
- 239000001257 hydrogen Substances 0.000 claims description 4
- 229910052739 hydrogen Inorganic materials 0.000 claims description 4
- 238000000462 isostatic pressing Methods 0.000 claims description 4
- 238000002360 preparation method Methods 0.000 claims description 4
- 238000005245 sintering Methods 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 238000011049 filling Methods 0.000 claims description 3
- 238000005266 casting Methods 0.000 claims description 2
- 238000009461 vacuum packaging Methods 0.000 claims description 2
- 238000003723 Smelting Methods 0.000 claims 1
- 238000000280 densification Methods 0.000 claims 1
- 238000003825 pressing Methods 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 abstract description 15
- 239000010959 steel Substances 0.000 abstract description 15
- 230000000694 effects Effects 0.000 description 7
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000008595 infiltration Effects 0.000 description 4
- 238000001764 infiltration Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- FWQVINSGEXZQHB-UHFFFAOYSA-K trifluorodysprosium Chemical compound F[Dy](F)F FWQVINSGEXZQHB-UHFFFAOYSA-K 0.000 description 4
- LKNRQYTYDPPUOX-UHFFFAOYSA-K trifluoroterbium Chemical compound F[Tb](F)F LKNRQYTYDPPUOX-UHFFFAOYSA-K 0.000 description 4
- 229910001117 Tb alloy Inorganic materials 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
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- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 229920002545 silicone oil Polymers 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005347 demagnetization Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010892 electric spark Methods 0.000 description 1
- 230000002431 foraging effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
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- 238000010248 power generation Methods 0.000 description 1
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
Abstract
The invention provides a slotted neodymium-iron-boron magnet, which comprises a neodymium-iron-boron magnet square magnet which is not subjected to permeation treatment; and a groove arranged on the surface of the NdFeB magnet block; the heavy rare earth slurry is arranged in the tank. The neodymium-iron-boron magnet square magnet with the slotting structure has flexible and changeable slotting positions and simple operation, can be applied to different products by meeting the performance requirements of all parts, can reasonably select the slotting positions according to the requirements, improves the magnetic performance of different positions, greatly helps the motor to improve the torque output capacity and reduce the loss during high-speed operation, reduces the eddy current loss of magnetic steel, improves the motor efficiency and improves the temperature rise of a rotor. In addition, the invention further carries out diffusion treatment on the slotted NdFeB magnetic steel which is not subjected to the permeation diffusion treatment, thereby reducing the usage amount of heavy rare earth diffusion sources and lowering the cost of the motor.
Description
Technical Field
The invention belongs to the technical field of preparation of neodymium-iron-boron magnets, relates to a slotted neodymium-iron-boron magnet and a neodymium-iron-boron magnet, and particularly relates to a low-eddy-current-loss neodymium-iron-boron magnet.
Background
The sintered NdFeB rare earth permanent magnet has excellent hard magnetic property and has wide application in the fields of new energy automobiles, intelligent communication, wind power generation and the like. In recent years, sintered neodymium-iron-boron magnets are continuously improved to have more excellent magnetic properties, and particularly have stronger magnetic field strength, higher coercivity and high-temperature resistance, so that the sintered neodymium-iron-boron magnets are widely applied to permanent magnet motors, but have certain defects as permanent magnet materials.
In motor applications, with the increase of the motor rotation speed or power, the eddy current effect exists in the neodymium-iron-boron magnet, which in turn causes the temperature to rise, and in the worst case, the neodymium-iron-boron magnet material may be demagnetized, thereby greatly reducing the performance of the motor. When the neodymium-iron-boron magnet is applied to a motor, the magnetic performance of the neodymium-iron-boron magnet can be attenuated to a certain extent along with the temperature rise of the motor operation, and the magnetic performance attenuation of different positions of the neodymium-iron-boron magnet is also different due to the temperature difference of different positions of the motor, but in the actual production process of the neodymium-iron-boron magnet, in order to ensure the magnetic performance of the region with the highest temperature, the performance of the whole magnet can always meet the magnetic performance attenuation requirement of the region with the highest temperature, so that the improvement of the residual magnetism of the neodymium-iron-boron magnet steel and the reduction of the cost are hindered to a certain extent.
In the prior art, most of motor permanent magnets usually adopt neodymium-iron-boron materials with higher coercive force and remanence, the conductivity is high, the heat resistance is poor, the eddy current loss of the permanent magnets is less than copper loss and iron loss in most cases, but for high-speed and high-power density motors and motors with closed structures, the eddy current loss of the neodymium-iron-boron permanent magnets can cause larger temperature rise of rotor parts of the motors, and even cause irreversible demagnetization of the permanent magnets in severe cases, which is fatal to the permanent magnet motors.
Therefore, on the premise of not affecting the use of the motor, the eddy current loss of the NdFeB magnetic steel is effectively reduced, the consumption of heavy rare earth is effectively reduced, and the cost of the whole magnetic steel is reduced, so that the motor is one of the problems to be solved by the technicians in the field.
Disclosure of Invention
In view of the above, the technical problem to be solved by the invention is to provide a slotted neodymium-iron-boron magnet and a neodymium-iron-boron magnet, in particular to a high-performance and low-eddy-current-loss neodymium-iron-boron magnet.
The invention provides a slotted neodymium-iron-boron magnet, which comprises a neodymium-iron-boron magnet square magnet which is not subjected to permeation treatment; and a groove arranged on the surface of the NdFeB magnet block;
the heavy rare earth slurry is arranged in the tank.
Preferably, the number of slots comprises 1 or more;
the plane size of the groove is 0.05-1.0 mm;
the depth of the groove is 1% -80% of the thickness of the neodymium-iron-boron magnet;
the shape of the groove comprises one or more of a rectangular groove, a V-shaped groove, a U-shaped groove and a round groove.
Preferably, the grooves of the magnet surface comprise through grooves and/or non-through grooves in the direction of the magnet plane;
the grooves are non-through grooves in the vertical direction of the magnet;
when the number of the grooves is multiple, the spacing between the grooves comprises equal spacing and/or unequal spacing;
the spacing is 0.5-100 mm.
Preferably, the included angle between the length direction of the groove and any side of the plane of the magnet where the groove is positioned is 0-90 degrees;
the grooved neodymium-iron-boron magnet has a grooved surface comprising one or more.
Preferably, the surface with the grooves comprises one or more surfaces perpendicular to the direction of orientation of the neodymium-iron-boron magnet and/or one or more surfaces parallel to the direction of orientation of the neodymium-iron-boron magnet;
the slotting mode comprises one or more of multi-line slotting, electric spark slotting, grinding wheel slotting, inner circle cutting slotting, outer circle cutting slotting and water jet cutting slotting.
Preferably, the heavy rare earth slurry comprises a heavy rare earth material and a solvent;
the heavy rare earth material comprises one or more of terbium powder, terbium fluoride powder, dysprosium fluoride powder and dysprosium and/or terbium-containing heavy rare earth alloy powder;
the solvent comprises one or more of gasoline, ethanol, acrylic acid and epoxy paint;
in the heavy rare earth slurry, the mass ratio of the heavy rare earth material to the solvent is 1: (2-6).
Preferably, the general formula of the heavy rare earth alloy powder is HRE-X;
the HRE includes Dy and/or Tb;
the X includes one or more of Pr, nd, al, cu, ga, ni, co, fe, zr, nb, ti, hf, W and V.
The invention provides a neodymium-iron-boron magnet, which is obtained by carrying out grain boundary diffusion treatment on the slotted neodymium-iron-boron magnet according to any one of the technical schemes.
Preferably, the grain boundary diffusion treatment includes performing a heat treatment at a first temperature and performing a diffusion treatment at a second temperature;
the first temperature is 350-450 ℃;
the time of the heat treatment is 3-5 hours;
the second temperature is 710-1000 ℃;
the diffusion treatment time is 1-50 h.
Preferably, the grain boundary diffusion treatment further comprises an aging treatment step;
the temperature of the aging treatment is 400-600 ℃;
the time of the aging treatment is 4-6 hours;
the neodymium-iron-boron magnet is a low-eddy-current-loss neodymium-iron-boron magnet.
The invention provides a slotted neodymium-iron-boron magnet, which comprises a neodymium-iron-boron magnet square magnet which is not subjected to permeation treatment; and a groove arranged on the surface of the NdFeB magnet block; the heavy rare earth slurry is arranged in the tank. Compared with the prior art, the invention designs the neodymium-iron-boron magnet block with the slotting structure, the slotting position is flexible and changeable, the operation is simple, the requirements on performance of all parts are met, the neodymium-iron-boron magnet block is applied to different products, the slotting position can be reasonably selected according to the requirements, the magnetic performance of different positions is improved, the high-speed running of the motor is greatly facilitated, the torque output capacity is improved, the loss is reduced, the eddy current loss of magnetic steel is reduced, the motor efficiency is improved, and the temperature rise of a rotor is improved. In addition, the invention further carries out diffusion treatment on the slotted NdFeB magnetic steel which is not subjected to the permeation diffusion treatment, thereby reducing the usage amount of heavy rare earth diffusion sources and lowering the cost of the motor.
Experimental results show that after the slotted neodymium iron boron magnetic steel which is not subjected to permeation diffusion treatment is adopted, heavy rare earth alloy powder is filled in a slot for diffusion treatment, the coercive force is improved by 9-12 KOE, the concentration of heavy rare earth on the surface of the slot is far higher than that in the magnet, and the coercive force of the magnet is also that in the magnet. Compared with the conventional magnet surface diffusion, the adoption of the slotted diffusion mode can save the usage amount of heavy rare earth by more than 10 percent. Compared with a conventional non-grooved diffusion magnet, the permeable grooved magnet steel has the advantages that in the running process of the motor, the eddy current effect of the magnet is reduced by more than 20%, and the temperature rise of the motor caused by the eddy current effect is reduced by more than 20 ℃.
Drawings
FIG. 1 is a schematic diagram of a slotted magnet provided in an embodiment of the present invention;
fig. 2 is a schematic diagram of the rare earth filling of the slotted magnet provided by the embodiment of the invention.
Detailed Description
For a further understanding of the present invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are merely intended to illustrate further features and advantages of the invention and are not limiting of the invention claims.
All the raw materials of the present invention are not particularly limited in their sources, and may be purchased on the market or prepared according to conventional methods well known to those skilled in the art.
All the raw materials of the present invention are not particularly limited in purity, and the present invention preferably adopts conventional purity used in the field of industrial pure or neodymium iron boron magnets.
The invention provides a slotted neodymium-iron-boron magnet, which comprises a neodymium-iron-boron magnet square magnet which is not subjected to permeation treatment;
and a groove arranged on the surface of the NdFeB magnet block;
the heavy rare earth slurry is arranged in the tank.
In the present invention, the number of the grooves preferably includes 1 or more.
In the present invention, the planar dimensions of the grooves are preferably 0.05 to 1.0mm, more preferably 0.1 to 0.6mm, still more preferably 0.1 to 0.5mm, still more preferably 0.1 to 0.3mm.
In the present invention, the depth of the groove is preferably 1% to 80%, more preferably 5% to 60%, and still more preferably 20% to 50% of the thickness of the neodymium-iron-boron magnet. In particular, the thickness according to the invention is preferably the thickness of the product in the cutting direction. The depth of the groove may be expressed as (1/100 to 80/100) × Hmm. (H represents the thickness of the magnet product, [1/100 to 80/100 ] H ] represents the depth of the slot in millimeters).
In the present invention, the shape of the groove includes one or more of a rectangular groove, a V-groove, a U-groove, and a circular groove, and more preferably a rectangular groove, a V-groove, a U-groove, or a circular groove.
In the present invention, the grooves of the magnet surface preferably include through grooves and/or non-through grooves, more preferably through grooves or non-through grooves, in the direction of the magnet plane.
In the present invention, the grooves are preferably not through grooves in the vertical direction of the magnet.
In the present invention, when the number of the grooves is plural, the pitch between the grooves preferably includes an equal pitch and/or an unequal pitch, and more preferably an equal pitch or an unequal pitch.
In the present invention, the pitch is preferably 0.5 to 100mm, more preferably 1 to 80mm, still more preferably 4 to 40mm, still more preferably 4 to 20mm.
In the present invention, the angle between the longitudinal direction of the slot and any side of the plane of the magnet where the slot is located is preferably 0 ° to 90 °, more preferably 20 ° to 70 °, and even more preferably 40 ° to 50 °. Specifically, the angle may be 1 ° to 89 °, or 3 ° to 88 °, or 5 ° to 85 °, or 7 ° to 83 °.
In the present invention, the grooved neodymium-iron-boron magnet preferably includes one or more of the grooved surfaces.
In the present invention, the surface having the grooves preferably includes one or more surfaces perpendicular to the direction of orientation of the neodymium-iron-boron magnet, and/or one or more surfaces parallel to the direction of orientation of the neodymium-iron-boron magnet, more preferably one or more surfaces perpendicular to the direction of orientation of the neodymium-iron-boron magnet, or one or more surfaces parallel to the direction of orientation of the neodymium-iron-boron magnet
In the present invention, the slotting means preferably includes one or more of multi-line slotting, spark slotting, grinding wheel slotting, inner circle cutting slotting, outer circle cutting slotting and water jet cutting slotting, more preferably multi-line slotting, spark slotting, grinding wheel slotting, inner circle cutting slotting, outer circle cutting slotting or water jet cutting slotting.
In the present invention, the heavy rare earth slurry preferably includes a heavy rare earth material and a solvent.
In the present invention, the heavy rare earth material preferably includes one or more of terbium powder, terbium fluoride powder, dysprosium fluoride powder, and dysprosium and/or terbium-containing heavy rare earth alloy powder, more preferably one of terbium powder, terbium fluoride powder, dysprosium fluoride powder, and dysprosium and/or terbium-containing heavy rare earth alloy powder.
In the present invention, the solvent preferably includes one or more of gasoline, ethanol, acrylic acid, and epoxy paint, more preferably gasoline, ethanol, acrylic acid, or epoxy paint.
In the heavy rare earth slurry, the mass ratio of the heavy rare earth material to the solvent is preferably 1: (2 to 6), more preferably 1: (2.5 to 5.5), more preferably 1: (3 to 5), more preferably 1: (3.5-4.5).
In the invention, the general formula of the heavy rare earth alloy powder is preferably HRE-X.
In the present invention, the HRE preferably includes Dy and/or Tb.
In the present invention, the X preferably includes one or more of Pr, nd, al, cu, ga, ni, co, fe, zr, nb, ti, hf, W and V, more preferably Pr, nd, al, cu, ga, ni, co, fe, zr, nb, ti, hf, W or V.
The invention provides a neodymium-iron-boron magnet, which is obtained by carrying out grain boundary diffusion treatment on the slotted neodymium-iron-boron magnet according to any one of the technical schemes.
In the present invention, the grain boundary diffusion treatment preferably includes a heat treatment at a first temperature and a diffusion treatment at a second temperature.
In the present invention, the first temperature is preferably 350 to 450 ℃, more preferably 370 to 430 ℃, and still more preferably 390 to 410 ℃.
In the present invention, the time of the heat treatment is preferably 3 to 5 hours, more preferably 3.2 to 4.8 hours, still more preferably 3.5 to 4.5 hours, still more preferably 3.2 to 4.3 hours.
In the present invention, the second temperature is preferably 710 to 1000 ℃, more preferably 760 to 950 ℃, and still more preferably 810 to 900 ℃.
In the present invention, the time of the diffusion treatment is preferably 1 to 50 hours, more preferably 5 to 40 hours, and still more preferably 10 to 30 hours.
In the present invention, the grain boundary diffusion treatment preferably further includes an aging treatment step.
In the present invention, the temperature of the aging treatment is preferably 400 to 600 ℃, more preferably 420 to 580 ℃, and still more preferably 450 to 550 ℃.
In the present invention, the aging treatment is preferably performed for a period of 4 to 6 hours, more preferably 4.2 to 5.8 hours, still more preferably 4.5 to 5.5 hours, and still more preferably 4.8 to 5.3 hours.
In the present invention, the neodymium-iron-boron magnet is preferably a low eddy current loss neodymium-iron-boron magnet.
The invention is a complete and refined whole technical scheme, better guarantees the performance of the neodymium-iron-boron magnet, improves the performance of the neodymium-iron-boron magnet for reducing eddy current loss, and the preparation method thereof preferably comprises the following steps:
the invention provides a preparation method of a slotted neodymium-iron-boron magnet, which comprises the steps of slotting on the surface of a neodymium-iron-boron magnet square magnet which is not subjected to permeation treatment, wherein the number of the slotted magnet is at least 1, the number of the slotted magnets is larger than zero, the width of the slotted is preferably 0.05-1.0 mm, the diameter of an opening is not zero, and the depth is (1/100-80/100) H mm; (the plane may be through or not).
In particular, the grooved face may be on any one or more surfaces of the magnet, preferably one or both surfaces perpendicular to the direction of orientation.
Specifically, the depth of the groove is more preferably (5/100-60/100) × Hmm, and most preferably (10/100-40/100) ×h mm.
Specifically, the width of the slit is more preferably 0.10 to 0.6mm, and most preferably 0.10 to 0.3mm.
In particular, the grooves may be equally and unequally spaced, with a spacing of 0.5 to 100mm, more preferably 4 to 40mm, and most preferably 4 to 20mm.
In particular, the grooves are at an angle of 0 ° to 90 ° (inclusive of 0 ° and 90 °) to either side of the surface on which they are located.
In particular, the groove shape includes, but is not limited to, rectangular, V-shaped, U-shaped.
In particular, the grooves on the same surface may be arranged in parallel or not.
Specifically, the neodymium-iron-boron magnet block magnet before diffusion treatment is prepared into heavy rare earth slurry, and the heavy rare earth slurry is filled in a groove formed in the neodymium-iron-boron magnet.
And drying, diffusing and aging the neodymium-iron-boron magnet filled with the heavy rare earth slurry to obtain the neodymium-iron-boron magnet with good performance.
Specifically, the heavy rare earth slurry comprises a heavy rare earth substance and a solvent, wherein the solvent is one or more selected from gasoline, ethanol, acrylic acid and epoxy paint. The mass ratio of the heavy rare earth substance to the solvent is 1: (2-6). The heavy rare earth substance is selected from one or more of terbium powder, terbium fluoride powder, dysprosium fluoride powder and heavy rare earth alloy powder HRE-X.
Specifically, the heavy rare earth content of the surface grain boundary of the diffused magnet is higher than that of the inside of the magnet, and the coercive force of the surface layer of the magnet is higher than that of the inside of the magnet.
Specifically, in the heavy rare earth alloy powder HRE-x, the HRE at least contains at least one of Dy and Tb simple substances.
Specifically, in the heavy rare earth alloy powder HRE-x, wherein x is at least one of Pr, nd, al, cu, ni, co, fe, zr, nb, ti, hf, W, V.
Specifically, the coercivity after diffusion treatment is increased by 8KOE to 13KOE relative to the coercivity before diffusion treatment. It may be 1KOe to 12KOe, 3KOe to 10KOe, or 5KOe to 7KOe.
Specifically, the rare earth content of the surface magnet of the groove is higher than that of the interior of the magnet, and the coercive force is also higher than that of the interior of the magnet;
specifically, the magnet slotting is cleaned before and after diffusion, and sealing or unsealing treatment can be performed after the diffusion treatment is finished.
Specifically, the grain boundary diffusion treatment specifically includes:
and (3) preserving the temperature of the neodymium iron boron magnet material in a vacuum infiltration furnace for 3-5 hours at the temperature of 350-450 ℃, removing and drying the organic solvent, and then heating to 710-1000 ℃ and preserving the temperature for 1-50 hours.
Specifically, the aging treatment is carried out at 400-600 ℃ for 4-6 hours.
The steps of the invention provide a low eddy current loss neodymium iron boron magnet. The neodymium-iron-boron magnet square magnet with the slotting structure has flexible and changeable slotting positions and simple operation, can be applied to different products by meeting the performance requirements of all parts, can reasonably select the slotting positions according to the requirements, improves the magnetic performance of different positions, greatly helps the motor to improve the torque output capacity and reduce the loss during high-speed operation, reduces the eddy current loss of magnetic steel, improves the motor efficiency and improves the temperature rise of a rotor. In addition, the invention further carries out diffusion treatment on the slotted NdFeB magnetic steel which is not subjected to the permeation diffusion treatment, thereby reducing the usage amount of heavy rare earth diffusion sources and lowering the cost of the motor.
Experimental results show that after the slotted neodymium iron boron magnetic steel which is not subjected to permeation diffusion treatment is adopted, heavy rare earth alloy powder is filled in a slot for diffusion treatment, the coercive force is improved by 9-12 KOE, the concentration of heavy rare earth on the surface of the slot is far higher than that in the magnet, and the coercive force of the magnet is also that in the magnet. Compared with the conventional magnet surface diffusion, the adoption of the slotted diffusion mode can save the usage amount of heavy rare earth by more than 10 percent. Compared with a conventional non-grooved diffusion magnet, the permeable grooved magnet steel has the advantages that in the running process of the motor, the eddy current effect of the magnet is reduced by more than 20%, and the temperature rise of the motor caused by the eddy current effect is reduced by more than 20 ℃.
For further explanation of the present invention, a slotted neodymium-iron-boron magnet and a neodymium-iron-boron magnet provided by the present invention are described in detail below with reference to examples, but it should be understood that these examples are implemented on the premise of the technical scheme of the present invention, and detailed implementation and specific operation procedures are given, which are only for further explanation of the features and advantages of the present invention, and not limitation of the claims of the present invention, and the scope of protection of the present invention is not limited to the examples described below.
Comparative example 1
The casting temperature is 1040-1060 ℃ through batching and medium-frequency vacuum melting, the R-T-B neodymium iron boron alloy cast sheet is crushed by a hydrogen embrittlement method, and the fine powder after hydrogen embrittlement is crushed again to obtain airflow powder grinding. Wherein the press forming includes: and (3) compacting the air-flow powder in a magnetic field by secondary compacting through an isostatic press. The magnetic induction intensity in the magnetic field is 1.7-1.9T. The molding density after compression molding in a magnetic field is 3 to 4.4g/cm 3 Vacuum packaging the pressed compact, and isostatic pressing the obtained pressed compact under 100-250 MPa to obtain a more compact pressed compact with the density of 4.8-5.2 g/cm 3 . Sintering the pressed compact subjected to isostatic pressing by using a vacuum heat treatment furnace, wherein the sintering temperature is 1000-1200 ℃; the sintering time is 180-600 min. And then heat treatment is carried out, the temperature is 400-700 ℃, and the time is 180-300 min. Obtaining a 52M magnet; the components of the magnet are: 30.2% PrNd,0.2% Dy, specification: 40 x 25 x 7.0mm.
The performance of the magnet is tested according to GB/T-3217-2013 magnetic test method of permanent magnet (hard magnetic) material, and the detection results are shown in Table 1:
table 1 magnet magnetic properties data sheet
| Sample species | Br(KGs) | HCJ(KOe) | Hk/HCj | (BH)max(MGOe) |
| Comparative example 1 substrate | 14.25 | 14.8 | 0.984 | 49.34 |
Processing the sintered blank into magnets with the thickness of 40.05 x 25.05 x 7.05mm, and then taking a plurality of comparison samples to respectively process the magnets into the grooves with the thickness of 1.8mm and 3.5mm on the surface with the thickness of 40.05mm x 25.05mm in the vertical orientation direction by adopting multiple lines; the groove widths are respectively 0.2mm and 0.4mm; the slot spacing is 4mm and 5mm respectively, and the slotted magnet is shown in figure 1.
Fig. 1 is a schematic and schematic diagram of a slotted magnet provided by an embodiment of the present invention. Wherein S: groove depth, T: groove spacing, D: the groove width.
Cleaning the magnet after grooving and foreign matter in the groove; preparing metal terbium alloy powder with average granularity of 2-10 microns, pouring the terbium alloy powder into epoxy paint in a glove box protected by nitrogen, wherein the weight ratio of the terbium alloy powder to gasoline is 1:3, and then uniformly stirring for standby.
Coating heavy rare earth alloy slurries with terbium contents of 0.5wt.%, 0.6wt.%, and 0.7wt.% on two surfaces of 40.05mm by 25.05mm of some processed magnets in a vertical orientation direction respectively for subsequent diffusion;
samples of different groove depths, groove widths and groove spacings were taken and heavy rare earth alloy slurries with terbium contents of 0.5wt.%, 0.6wt.%, 0.7wt.% were uniformly filled in the grooves and on the other 40.05mm 25.05mm faces without grooves, respectively, for subsequent diffusion use, as shown in fig. 2.
Fig. 2 is a schematic diagram of the rare earth filling of the slotted magnet provided by the embodiment of the invention. Wherein E: heavy rare earth alloy compounds.
And then placing the samples coated with the heavy rare earth alloy and the comparative samples into a vacuum diffusion furnace, firstly preserving heat at 400 ℃ for 4 hours to dry the silicone oil, discharging the silicone oil into the diffusion furnace through a vacuum system of the vacuum furnace, then heating to 700-1000 ℃ for grain boundary diffusion treatment, wherein the diffusion time is 30 hours, quenching to below 80 ℃ after diffusion, then heating to 500 ℃ for aging treatment, wherein the aging time is 5 hours, and quenching to below 80 ℃ after aging treatment, and discharging the treated samples.
Some of the samples after the above diffusion treatment were wire-cut into 8×4×7mm samples, and the performance of the magnets was tested according to the conventional art, and the results are shown in table 2.
Table 2 sample magnetic properties data sheet
As can be seen from table 2: the same heavy rare earth penetration amount, the coercive force of the slotted magnet is about 1KOE higher than that of the non-slotted magnet; under the condition of reaching the same coercive force, the dosage of the heavy rare earth of the slotted magnet is more than 10 percent less than that of the non-slotted magnet. The slotting and infiltration mode is adopted, slotting and infiltration can be carried out at any position according to the magnet requirements of different motors, the local coercive force is improved, the demagnetizing resistance of the magnet is improved, the heavy rare earth consumption of the magnet is reduced, and the rare heavy rare earth resource is protected.
Performing magnetic moment test on the magnet subjected to diffusion post-treatment, obtaining magnetic moment relative values of different slotted magnets, loading the slotted magnets into a motor, operating under a certain load and output power, and testing temperature rise of the motor after a certain time of operation, wherein data are shown in the following table 3;
table 3 comparative example data table of relative magnetic moment of magnet after diffusion treatment and motor temperature rise
As can be seen from table 3: the slotting penetration of the surface of the magnet is simple, practical and efficient, and the magnet can be produced in batches; the temperature rise caused by the eddy effect in the running process of the motor can be effectively reduced, and the damage of the motor caused by overhigh temperature is avoided; the temperature rise of the motor is optimally controlled, so that the coercive force requirement of the motor on the magnet can be reduced, the heavy rare earth consumption of the magnet is further reduced, the comprehensive cost of the motor is reduced, and the rare heavy rare earth resource is protected.
As can be seen from tables 2 and 3, by means of slotted infiltration,
1. different heavy rare earth additives can be added at different positions of the same product, so that the permeation additives of the product are more diversified;
2. the heavy rare earth consumption of the product can be effectively reduced, and the motor cost is reduced;
3. the performance of the magnetic steel is more fit with the actual service environment of the motor, and the attenuation of the magnetic steel at high temperature is reduced
4. Effectively reduces the temperature rise of the motor under the high-power running condition
The comprehensive performance is ensured to be optimal, and the effect of reducing the penetration dosage of heavy rare earth and improving the performance of the product can be achieved through the structural design of the grooves.
The foregoing has outlined, rather broadly, the principles and embodiments of the present invention in order that the detailed description of the invention may be better understood, and in order that the present invention may be practiced by anyone skilled in the art, including in any regard to making and using any devices or systems, and in any implementation of any combination of the methods. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims. The scope of the patent protection is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
Claims (7)
1. A method for reducing eddy current loss of a neodymium-iron-boron magnet, comprising the steps of:
slotting the sintered magnet blank, then filling heavy rare earth slurry into the slots to obtain slotted neodymium-iron-boron magnets, and performing grain boundary diffusion treatment on the slotted neodymium-iron-boron magnets;
the included angle between the length direction of the groove and any side of the plane of the magnet where the groove is positioned is 20-70 degrees;
the surfaces with the grooves comprise one or more surfaces perpendicular to the direction of orientation of the neodymium-iron-boron magnet and/or one or more surfaces parallel to the direction of orientation of the neodymium-iron-boron magnet;
the width of the groove is 0.1-0.3 mm;
the depth of the groove is 1% -80% of the thickness of the neodymium-iron-boron magnet;
the space between the grooves is 20-100 mm;
the heavy rare earth slurry comprises a heavy rare earth material and a solvent;
the heavy rare earth material comprises dysprosium and/or terbium-containing heavy rare earth alloy powder;
in the heavy rare earth slurry, the mass ratio of the heavy rare earth material to the solvent is 1: (2-6);
the general formula of the heavy rare earth alloy powder is HRE-X;
the HRE is Dy and/or Tb;
the X is one or more of Pr, nd, al, cu, ga, ni, co, fe, zr, nb, ti, hf, W and V;
the preparation process of the sintered magnet blank comprises the following steps:
crushing R-T-B neodymium iron boron alloy cast sheets by a hydrogen embrittlement method through burdening and medium-frequency vacuum smelting, wherein the casting temperature is 1040-1060 ℃, crushing the hydrogen embrittled fine powder again, and then carrying out an airflow grinding process; after the airflow powder is pressed and formed in a magnetic field, performing secondary pressing and densification through an isostatic pressing machine, vacuum packaging the obtained pressed compact, isostatic pressing the obtained pressed compact, and sintering the isostatic pressed compact through a vacuum heat treatment furnace;
the grain boundary diffusion treatment includes performing a heat treatment at a first temperature and performing a diffusion treatment at a second temperature;
the first temperature is 350-450 ℃;
the time of the heat treatment is 3-5 hours;
the second temperature is 710-1000 ℃;
the diffusion treatment time is 1-50 h.
2. The method of claim 1, wherein the number of slots comprises a plurality;
the shape of the groove comprises one or more of a rectangular groove, a V-shaped groove, a U-shaped groove and a round groove.
3. The method according to claim 1, wherein the grooves of the magnet surface comprise through grooves and/or non-through grooves in the direction of the magnet plane;
the grooves are non-through grooves in the vertical direction of the magnet;
the number of the grooves is plural, and the interval between the grooves comprises equal interval and/or unequal interval.
4. The method of claim 1, wherein the grooved neodymium-iron-boron magnet has grooved surfaces comprising one or more.
5. The method of claim 1, wherein the slotting mode comprises one or more of multi-wire slotting, spark slotting, grinding wheel slotting, inner circle cutting slotting, outer circle cutting slotting, and water jet cutting slotting.
6. The method of claim 1, wherein the solvent comprises one or more of gasoline, ethanol, acrylic, and epoxy paint.
7. The method according to claim 1, further comprising an aging step after the grain boundary diffusion treatment;
the temperature of the aging treatment is 400-600 ℃;
the aging treatment time is 4-6 hours;
the neodymium-iron-boron magnet is a low-eddy-current-loss neodymium-iron-boron magnet.
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| CN202210503926.7A CN114823025B (en) | 2022-05-10 | 2022-05-10 | Low-eddy-current-loss neodymium-iron-boron magnet |
| PCT/CN2022/098613 WO2023216358A1 (en) | 2022-05-10 | 2022-06-14 | Neodymium-iron-boron magnet having low eddy current loss |
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